<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>
<script>
    var income =prompt("收入");
    var outcome;
    if(income<2500){
        alert(0);
    }else if(income<4000){
        outcome = (income-2500)*0.1;
        alert(outcome);
    }else if(income<8000){
        outcome = (income-4000)*0.15+150;
        alert(outcome);
    }else if(income<10000){
        outcome = (income-8000)*0.175+2000*0.15+150;
        alert(outcome);
    }else{
        outcome = (income-10000)*0.2+2000*0.175+2000*0.15+150;
        alert(outcome);
    }
</script>